Sherwins: Mammoth Rock Area

Submission Info
Volunteer Observer
Friday, February 10, 2017 - 11:00am
Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
37° 36' 43.7688" N, 118° 59' 39.3" W
Snowpit Observations
More detailed information about the snowpack: 

Toured from the end of Old Mammoth Road. Parking area adequately plowed. 6-8" new snow approaching Mammoth Rock. Light winds NW with some visible snow transport in exposed areas. Light snow falling (S-1) throughout tour with periods of heavier precip (S1-S2). Hand pits revealed good bonding between new snow and old wet snow surface. Some separation in new snow. Probing revealed a right side up snowpack. Pit dug on NE aspect NTL (approx. 9500') in an area with previous wind transport. Moderate force in column tests produced Q3 shears and non-propagating results within the new snow, and within the old rain soaked snow. See attached profile. We observed a slightly stiffer wind effected snow surface near the ridgetop, but did not experience any shooting cracks or whumphing. These newly formed windslabs were isolated to just beneath ridgetop in open areas and were still quite soft. At ridgetop the snow surface was more supportable with ski penetration reducing to just a few centimeters.

Visibility was poor at ridgetop with light winds. Newly formed cornices were observed along the ridge from Mammoth Rock Bowl to the top of the Hose. Small crowns in the vicinity of The Hose were visible from a short distance but difficult to discern in the flat light. Another skier reported skiing bed surface in the Hose and finding large blocky debris in the Hose itself and the trees nearby, presumably from a recent interstorm avalanche. (Possibly cornice collapse?) 

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Accumulation rate: 
Less than 1 in. per hour
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